Organic luminescence device with anti-reflection layer and organic luminescence device package

ABSTRACT

For realizing an organic luminescence device of a high efficiency, the present invention provides an organic luminescence device having an anti-reflection film on a transparent electrode or on a moisture prevention layer.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a division of application Ser. No. 11/099,623, filedApr. 6, 2005 now U.S. Pat. No. 7,187,121, which in turn, is a divisionof application Ser. No. 10/406,273, filed Apr. 4, 2003 now abandoned.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an organic luminescence device havingat least an organic compound layer between an anode and a cathode, andan organic luminescence device array and an organic luminescence devicepackage.

2. Related Background Art

An organic luminescence device means a so-called organicelectroluminescence device in which a current flowing between a cathodeand an anode causes light emission of an organic compound presentbetween the electrodes.

(First Background Art)

FIG. 1 shows a general cross-sectional structure of an organicluminescence device, in which shown are a substrate 1, an electrode 2, ahole transporting layer 3, a light emitting layer 4, an electroninjecting layer 5, and a transparent electrode 6.

In such organic luminescence device, electrons injected from thetransparent electrode 6 through the electron injecting layer 5 into thelight emitting layer 4 combine with positive holes injected from theelectrode 2 through the hole transporting layer 3 into the lightemitting layer 4 to form excitons, and the device utilizes light emittedwhen the excitons return to a ground state. The light is emitted to theexterior through the transparent electrode 6.

(Second Background Art)

FIG. 2 shows a general cross-sectional structure of an organicluminescence device array having a plurality of such organicluminescence devices, in which shown are a substrate 1, an electrode 2,a hole transporting layer 3, a light emitting layer 4, an electroninjecting layer 5, and a transparent electrode 6, an insulating member 7provided in an isolating area present between the respective organicluminescence devices, a wiring 8 connected to the electrode 2 of eachorganic luminescence device, and a resinous member 9. FIG. 2 shows adevice having five organic luminescence devices as an example, but thenumber of the organic luminescence devices provided in an array devicecan be arbitrarily selected.

(Third Background Art)

FIG. 3 shows a general cross-sectional structure of an organicluminescence device and a package therefor, in which shown are asubstrate 1, an electrode 2, a hole transporting layer 3, a lightemitting layer 4, an electron injecting layer 5, and a transparentelectrode 6 and a case 14 for accommodating the organic luminescencedevice.

In such organic luminescence device, electrons injected from thetransparent electrode 6 through the electron injecting layer 5 into thelight emitting layer 4 combine with positive holes injected from theelectrode 2 through the hole transporting layer 3 into the lightemitting layer 4 to form excitons, and the device utilizes light emittedwhen the excitons return to a ground state.

(Drawbacks Associated with the First Background Art)

In such organic luminescence device, the transparent electrode 6 isformed by a material of a refractive index higher than that of air ornitrogen, constituting the external environment of the organicluminescence device. Therefore, the light emitted from the lightemitting layer 4 is reflected at a light emitting surface of thetransparent electrode 6, namely at the interface between the transparentelectrode and the air constituting the external environment in FIG. 1.For this reason, such organic luminescence device has been associatedwith a low efficiency of light emission to the exterior, and, in case ofemploying a transparent electrode 6 formed by a material of such highrefractive index, an external light falling on the organic luminescencedevice from the external environment is reflected at the interface ofthe transparent electrode 6 and the external environment, whereby, evenif the other electrode 2 formed at the substrate side is provided withmeans for preventing reflection of the external light, the externallight is reflected on the surface of the transparent electrode 6 tocause a mixing of the light emitted by the device and the reflectedlight of the external light thereby lowering the contrast of the organicluminescence device. Also in case a passivation film such as a SiN filmfor moisture prevention is formed on the transparent electrode 6, asimilar drawback is encountered because of a large difference in therefractive index between the SiN film and the air.

(Drawback Associated with the Second Background Art)

In an organic luminescence device array having a plurality of suchorganic luminescence devices, there is formed a wiring connected to theelectrode of each organic luminescence device, in an isolation area ofthe organic luminescence devices and under the organic luminescencedevices. In case an insulating member 7 provided in such isolation areaand a resinous member 9 on the substrate 1 are light transmissible, theexternal light entering the organic luminescence device array from theexternal environment is transmitted by the insulating member 7 in theisolation area and the resinous member 9 and is reflected by the wiring8. Also the external light may be reflected by such insulating member 7or resinous member 9. The light reflected in these portions is mixedwith the light emitted from the organic luminescence device to lower thecontrast thereof, whereby an image displayed by the device is deficientin visibility.

Also in a package accommodating the aforementioned organic luminescencedevice array in a case, in order to avoid the aforementioned drawback ofthe contrast loss by the reflection of the external light, it isnecessary to form a polarizing layer on a light emitting face of thecase. For this reason, the package of such organic luminescence devicearray is also associated with a drawback that the manufacture is complexand expensive.

(Drawback Associated with the Third Background Art)

In a package of such organic luminescence device, the light emitted fromthe light emitting layer 4 is transmitted by the transparent electrode6, and enters the light emitting face of the case 14 through anunrepresented atmospheric gas such as air or nitrogen. The case 14 isgenerally formed with a material such as glass or resin, of whichrefractive index is higher than of the atmospheric gas present betweenthe organic luminescence device and the case. Therefore, the lightemitted from the light emitting layer 4 is partly reflected at theinterface between the atmospheric gas and the light entering face of thecase 14. For this reason, such package of the organic luminescencedevice has been associated with a low efficiency of light emission tothe exterior.

Similarly, the transparent electrode 6 has a refractive index higherthan that of the unrepresented atmospheric gas. Therefore, the lightemitted from the light emitting layer 4 is partly reflected at theinterface between the transparent electrode 6 and the atmospheric gas,and such package of the organic luminescence device has been associatedwith a low efficiency of light emission to the exterior.

Furthermore, for the case 14, the material constituting the case 14 hasa refractive index higher than that of the air constituting the externalenvironment of the package, whereby the light from the externalenvironment (external light) is reflected on the face of the case 14,emitting the light. For this reason, the light emitted from the deviceis mixed with the external light at the interface between the externalenvironment and the case 14, whereby the organic luminescence packageitself has a low contrast.

SUMMARY OF THE INVENTION

In consideration of the foregoing, the present invention is to providean organic luminescence device of a high light-emitting efficiency tothe exterior and an organic luminescence device of a satisfactorycontrast.

More specifically, the present invention provides an organicluminescence device having at least a pair of mutually opposedelectrodes and an organic compound layer provided between the pairedelectrodes, wherein the organic luminescence device includes ananti-reflection layer on a transparent electrode on the light-emittingside of the electrodes.

Also, the present invention provides an organic luminescence devicehaving at least a pair of mutually opposed electrodes and an organiccompound layer provided between the paired electrodes, wherein the pairof electrodes are constituted by an electrode provided on the side of asubstrate and a transparent electrode constituting the other electrode,and the organic luminescence device includes a moisture preventing layeron the transparent electrode and an anti-reflection layer on themoisture preventing layer.

Also the present invention provides an organic luminescence device arrayhaving, on a substrate, a plurality of organic luminescence devicesseparated by isolation areas and each having a pair of mutually opposedelectrodes and an organic compound layer formed between the pairedelectrodes, wherein the array includes a wiring connected to the organicluminescence device under the organic luminescence device and in theisolation area, and, in the isolation area on the wiring, a member whichintercepts external light entering the organic luminescence device fromthe exterior and has a reflectance to the external light lower than thatof the wiring.

Also the present invention provides an organic luminescence device arrayhaving, on a substrate, a plurality of organic luminescence devicesseparated by isolation areas and each having a pair of mutually opposedelectrodes and an organic compound layer formed between the pairedelectrodes, wherein the array includes a wiring, connected to theorganic luminescence device, under the organic luminescence device andin the isolation area and a member bearing such wiring, and, such memberintercepts external light entering the organic luminescence device fromthe exterior and has a reflectance to the external light lower than thatof the wiring.

Also the present invention provides a package for an organicluminescence device with a high light-emitting efficiency to theexterior.

More specifically, the present invention provides a package for anorganic luminescence device including:

an organic luminescence device having a pair of electrodes mutuallyopposed on a substrate, and an organic layer formed between the pairedelectrodes, and

a case holding the organic luminescence device in an internal holdingspace, in which a light emitted from the organic luminescence device isemitted to the exterior through a light emitting side of the case;

wherein anti-reflection means is provided on a light-emitting face onthe light-emitting side among faces constituting the internal holdingspace of the case.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view showing a multilayer structure of an organicluminescence device of the background art;

FIG. 2 is a schematic view showing a structure of an organicluminescence device array of the background art;

FIG. 3 is a schematic view showing a structure of an organicluminescence device package of the background art;

FIG. 4 is a schematic view showing a multilayer structure of an organicluminescence device of the present invention;

FIG. 5 is a schematic view showing a multilayer structure of an organicluminescence device of the present invention;

FIG. 6 is a schematic view showing a multilayer structure of an organicluminescence device of the present invention;

FIG. 7 is a schematic view showing a multilayer structure of an organicluminescence device of the present invention;

FIG. 8 is a schematic view showing a multilayer structure of an organicluminescence device of the present invention;

FIG. 9 is a schematic view showing a multilayer structure of an organicluminescence device of the present invention;

FIG. 10 is a schematic view showing a multilayer structure of an organicluminescence device of the present invention;

FIG. 11 is a schematic view showing a multilayer structure of an organicluminescence device of the present invention;

FIG. 12 is a schematic view-showing a multilayer structure of an organicluminescence device of the present invention;

FIG. 13 is a schematic view showing a multilayer structure of an organicluminescence device of the present invention;

FIG. 14 is a schematic view showing a multilayer structure of an organicluminescence device of the present invention;

FIG. 15 is a schematic view showing a multilayer structure of an organicluminescence device of the present invention;

FIG. 16 is a schematic view showing a multilayer structure of an organicluminescence device of the present invention; and

FIG. 17 is a schematic view showing a multilayer structure of an organicluminescence device of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First Embodiment

An organic luminescence device according to a first embodiment of thepresent invention is provided with an anti-reflection layer 15 on atransparent electrode 6 serving as a light-emitting electrode. Suchanti-reflection layer may be of a single layer type or a multi layertype. FIG. 4 is a schematic cross-sectional view of an organicluminescence device of the first embodiment of the present invention, inwhich provided are a substrate 1, an electrode 2, a hole transportinglayer 3, a light emitting layer 4, an electron injecting layer 5, atransparent electrode 6, and an anti-reflection layer 15 to constitutean organic luminescence device of so-called top emission type.

The anti-reflection layer prevents the reflection of the light emittedfrom the light emitting layer at the interface between the transparentelectrode 6 and the external environment in which the organicluminescence device is present, thereby improving the light-emissionefficiency of the device.

The external environment means ordinary air, air with a reduced contentof oxygen or moisture, or an inert gas such as nitrogen.

In this embodiment, the anti-reflection layer may be of a single layertype or a multi layer type. An example of a particularly preferablyemployable material is SiO₂. The organic compound can be a known onesuch as Alq3 or α-NPD.

Also the organic layer between the electrodes can be, in addition to theforegoing, of plural layers such as a three-layer or five-layerstructure. Also the organic luminescence device of the presentembodiment may be applied to a display apparatus capable of full-colordisplay, constituted by light-emitting devices of RGB colors. Morespecifically, it may be applied to a display unit of a display device.The organic luminescence device of the present embodiment may beapplied, among such display devices, to a pixel unit (light-emittingunit) of a display panel of so-called active matrix drive, utilizingTFTs.

Second Embodiment

An organic luminescence device according to a second embodiment of thepresent invention includes, in an organic luminescence device having amoisture preventing layer on the transparent electrode 6 serving as thelight-emitting electrode, an anti-reflection layer on such moisturepreventing layer. Other configurations are the same as those in thefirst embodiment. FIG. 5 is a schematic cross-sectional view of anorganic luminescence device of the second embodiment of the presentinvention, in which provided are a substrate 1, an electrode 2, a holetransporting layer 3, a light emitting layer 4, an electron injectinglayer 5, a transparent electrode 6, an anti-reflection layer 15, and amoisture preventing layer 16, to constitute an organic luminescencedevice of so-called top emission type.

The anti-reflection layer prevents the reflection of the light emittedfrom the light emitting layer at the interface between the moisturepreventing layer 16 and the external environment in which the organicluminescence device is present, thereby improving the light-emissionefficiency of the device.

Third Embodiment

An organic luminescence device according to a third embodiment of thepresent invention utilizes, as an electrode provided at the substrateside, an electrode capable of preventing reflection of a light enteringthe device from the exterior, utilizing light absorption or by lightinterference. Other configurations are the same as those in the secondembodiment. FIG. 6 is a schematic cross-sectional view of an organicluminescence device of the third embodiment of the present invention, inwhich provided are a substrate 1, an electrode 22 which intercepts theexternal light and prevents reflection thereof, a hole transportinglayer 3, a light emitting layer 4, an electron injecting layer 5, atransparent electrode 6, an anti-reflection layer 15, and a moisturepreventing layer 16, to constitute an organic luminescence device ofso-called top emission type.

Thus, the organic luminescence device of the present embodiment isapplicable also to an organic luminescence device utilizing, as theelectrode at the substrate side, an electrode which is so constructed asto prevent reflection of the external light. Also since theanti-reflection layer prevents reflection of the emitted light as wellas the external light at the interface between the organic luminescencedevice and the external environment, the present embodiment provides ahigher light-emitting efficiency in comparison with other embodimentsand can provide an organic luminescence device of a very high contrast.

The light-emission efficiency of the foregoing embodiments in theconfigurations shown in FIGS. 4 to 6 can be estimated as follows.

Light reflection becomes larger and light transmission is lowered at aninterface where the constituting materials thereof show a largerdifference in the refractive indexes. More specifically, at theinterface between the transparent electrode 6 and the light emissionspace, for an ITO transparent electrode with a refractive index n6=2.0and a space of nitrogen or air with a refractive index nk=1, thereflectance is given by (n6−nk)²/(n6+nk)² and gives a reflection loss ofabout 11%.

In a device of a configuration having the moisture preventing layer 16on the transparent electrode 6, the moisture preventing layer 16 formedfor example by SiN has a reflective index n8 of about 2.3. Thedifference in the refractive indexes between the transparent electrode 6and the moisture preventing layer 16 is as small as about 0.3 which onlycauses a small reflection loss of 0.5% in a similar estimation, but thereflection loss at the interface between the moisture preventing layer16 and the light emission space, given by (n8−nk)²/(n8+nk)², amounts toabout 15.5%.

Thus, for improving the light-emission efficiency, it is necessary tosuppress the reflection loss and to improve the transmittance of lightemitted from the light emitting layer 4 to the upper space through thetransparent electrode 6 or the moisture preventing layer 16.

An anti-reflection film is effective for suppressing the reflectionloss. A known anti-reflection film utilizes a transparent material of alarge refractive index such as ZnS, CeO₂ or TiO₂ and a material of asmall refractive index such as LiF, CaF₂, MgF₂ or SiO₂ and is formed byalternately laminating the material of a larger refractive index and thematerial of a smaller refractive index (with mutually differentrefractive indexes) with each thickness obtained by dividing a designwavelength with (4× refractive index of material). In suchconfiguration, it is necessary to employ a material of a refractiveindex smaller than that of a material constituting the interface, as thematerial of the smaller refractive index in the anti-reflection film.For example, a three-pair anti-reflection film employing NaF or LiF(smaller refractive index) and TiO₂ (larger refractive index) (forexample, case surface/LiF/TiO₂/LiF/TiO₂/LiF/TiO₂) allows to reduce theabove-mentioned interfacial reflection loss to 1/10 or less.

In case the anti-reflection film 15 has a single layer structure, thereis selected a material having a refractive index lower than that of thematerial constituting the interfacial layer of which reflection loss isto be suppressed.

A contrast of a device can be evaluated by a following formula:C=1+B/(γ×A)wherein C is a contrast evaluation value, A is luminosity (ft-L) ofexternal light, B is luminosity (ft-L) of the device, and γ isreflectance (%) of the entire device.

It is therefore necessary to observe the device in a darker place (A)with a lowered reflectance (γ) and with a higher luminosity.

In practice, a difficulty may arise in an outdoor use. The luminosity ofthe external light may become several to ten and several times of thatof the device.

The reflection loss, which lowers the transmission, also reduces thecontrast. In the absence of the aforementioned anti-reflection film,because of a reflection of the external light of about 11 to 16%, thecontrast value becomes 10 or less even under the external light of aluminosity comparable to that of the device. On the other hand, thepresence of the aforementioned anti-reflection film, capable of reducingthe reflection of the external light to about 1%, can provide asatisfactory contrast value close to 100. However, in case the electrode2 has a high reflectance (for example 20% or higher), a sufficientimprovement in contrast cannot be attained due to the reflection of theexternal light by the electrode 2. A reflection of the external light of1% or less in the entire device can be attained by employing anelectrode 22 capable of intercepting the external light and preventingthe reflection of the external light (reflectance about 1%) as shown inFIG. 6.

EXAMPLES

In the following, there will be explained, with reference to theaccompanying drawings, preferred examples of the method for producingthe organic luminescence device of the present invention, but thepresent invention is not limited by such examples.

Example 1

FIG. 4 shows a first example, in which shown are a substrate 1, anelectrode 2, a hole transporting layer 3, a light emitting layer 4, anelectron injecting layer 5, a transparent electrode 6, and ananti-reflection layer 15.

On the substrate 1, a chromium film was formed by sputtering to obtainthe electrode 2. Then the substrate was subjected to ultrasonic rinsingin succession with acetone and isopropyl alcohol (IPA), then washed byboiling in IPA and dried. It was further subjected to UV/ozone washing.

Then a vacuum evaporation apparatus (manufactured by Shinku Kikou Co.)was used to form, on the substrate after washing, a film of αNPD havinga hole transporting property and represented by a following chemicalformula I

by vacuum evaporation to form the hole-transporting layer 3. The filmformation was conducted under a vacuum of 1.0×10⁻⁶ Torr, and a filmforming rate of 0.2-0.3 nm/sec. Then, on the hole-transporting layer 3,a film of an aluminum chelate (hereinafter called Alq3) represented bythe following chemical formula:

was formed by vacuum evaporation under the same conditions as those inthe formation of the hole-transporting layer 3, thereby obtaining alight-emitting layer 4. Then, on the light-emitting layer 4, a film ofaluminum-lithium as the electron-injecting layer 5 was formed by vacuumevaporation under the same conditions as those in the formation of thehole-transporting layer 3. Thereafter, on the electron-injecting layer5, a film of tin indium oxide (ITO) was formed by sputtering to obtainthe transparent electrode 6. Finally, on the transparent electrode 6, afilm of SiO₂ was formed by sputtering as an anti-reflection film(layer).

In this manner an organic luminescence device was prepared on thesubstrate 1, by forming the electrode 2, the hole-transporting layer 3,the light-emitting layer 4, the electron-injecting layer 5, thetransparent electrode 6, and the anti-reflection layer 15.

Subsequently, a DC voltage was applied to the organic luminescencedevice in order to investigate the light emission characteristicsthereof. As a result, it was confirmed that this device had an improvedlight-emitting efficiency in comparison with a device which is notprovided with the anti-reflection layer 15 on the transparent electrode6.

Example 2

FIG. 5 shows a second example, in which shown are a substrate 1, anelectrode 2, a hole transporting layer 3, a light emitting layer 4, anelectron injecting layer 5, a transparent electrode 6, ananti-reflection layer 15, and a moisture preventing layer 16.

Under conditions similar to those in the example 1 and on a chromiumfilm constituting the electrode 2, a film of αNPD was formed as thehole-transporting layer 3, and a film of Alq3 was formed as thelight-emitting layer 4. Then, a film of aluminum-lithium was formed asthe electron-injecting layer 5. Thereafter, on the electron-injectinglayer 5, a film of tin indium oxide (ITO) was formed by sputtering toobtain the transparent electrode 6. Then, on the transparent electrode6, a film of silicon nitride (SiN) was formed by sputtering as themoisture preventing layer 16. Finally, on the moisture preventing layer16, a film of SiO₂ was formed by sputtering as the anti-reflection film.

In this manner an organic luminescence device was prepared on thesubstrate 1, by forming the electrode 2, the hole-transporting layer 3,the light-emitting layer 4, the electron-injecting layer 5, thetransparent electrode 6, the anti-reflection layer 15, and the moisturepreventing layer 16.

Subsequently, a DC voltage was applied to the organic luminescencedevice in order to investigate the light emission characteristicsthereof. As a result, it was confirmed that this device had an improvedlight-emitting efficiency in comparison with a device which is notprovided with the anti-reflection layer 15 on the moisture preventinglayer 16.

Example 3

FIG. 6 shows a third example, in which shown are a substrate 1, anelectrode 22 which intercepts the external light, a hole transportinglayer 3, a light emitting layer 4, an electron injecting layer 5, atransparent electrode 6, an anti-reflection layer 15, and a moisturepreventing layer 16.

As the electrode 22 for intercepting the external light and preventingreflection of the external light, there may be employed an electrodeutilizing a light-absorbing black material such as carbon, or anelectrode capable of preventing reflection of the light entering thedevice from the exterior utilizing interference of light, as in a BlackLayer technology (Luxell Inc.).

Thicknesses of the electrodes and the layers were determined inconsideration of the light-emitting efficiency, so as to exhibit avisually desired display ability.

At first, on the substrate 1, a film of chromium was formed with athickness of 200 nm by sputtering, and films of indium tin oxide (ITO)of a thickness of 62.1 nm and chromium of a thickness of 4.3 nm wereformed thereon, thereby forming the electrode 9 capable of interceptingthe external light and preventing the reflection thereof utilizingoptical interference in three layers of chromium-ITO-chromium. Then,under conditions similar to those in the example 1 and on the electrode9 capable of intercepting the external light and preventing reflectionthereof, a film of αNPD was formed with a thickness of 50 nm as thehole-transporting layer 3, and a film of Alq3 was formed with athickness of 50 nm as the light-emitting layer 4. Then, a film ofaluminum-lithium was formed with a thickness of 1 nm as theelectron-injecting layer 5. Thereafter, on the electron-injecting layer5, a film of tin indium oxide (ITO) was formed with a thickness of 392nm by sputtering to obtain the transparent electrode 6. Then, on thetransparent electrode 6, a film of silicon nitride (SiN) was formed witha thickness of 1775 nm by sputtering as the moisture preventing layer16. Finally, on the moisture preventing layer 16, a film of SiO₂ wasformed with a thickness of 92.3 nm by sputtering as the anti-reflectionfilm.

In this manner an organic luminescence device was prepared on thesubstrate 1, by forming the electrode 9 capable of intercepting theexternal light and preventing reflection thereof, the hole-transportinglayer 3, the light-emitting layer 4, the electron-injecting layer 5, thetransparent electrode 6, the anti-reflection layer 15, and the moisturepreventing layer 16.

Then, reflectance was measured in case of introducing light (externallight) into the organic luminescence device from a direction of theanti-reflection layer. As a result this device showed a reflectance of1.6% or lower in a wavelength region of 450 to 650 nm. An organicluminescence device prepared for the purpose of comparison without theanti-reflection layer and subjected to the measurement of reflectance ina similar manner showed a reflectance as high as 10 to 15%.

Subsequently, a DC voltage was applied to the organic luminescencedevice in order to investigate the light emission characteristicsthereof. As a result, it was confirmed, because the electrode at thesubstrate side was capable of intercepting the external light andpreventing reflection thereof and the anti-reflection layer was providedon the moisture preventing layer, that this device showed a significantimprovement in the contrast of light emission, in comparison with adevice which is not provided with such layers.

FIG. 7 shows another example having a transparent cover member, in whichshown are an air layer 10 constituting a gaseous layer, and a coverglass 11 constituting a transparent cover member. The anti-reflectionlayer is formed by a SiO₂ layer of a refractive index 1.5, positionedbetween a passivation film (SiN) with a refractive index 2.1 and an airlayer of a refractive index 1.0. In this example, the reflection of theexternal light is reduced by a large difference in the refractive indexbetween the air layer and the passivation film (SiN), thereby improvingthe contrast of the organic luminescence device.

Formation of the anti-reflection layer according to the presentinvention allows to provide an organic luminescence device of a highefficiency, and an organic luminescence device of satisfactory contrast.

In the following there will be explained fourth to eighth embodimentsand fourth to eighth examples.

These embodiments and examples provide an organic luminescence devicearray having a plurality of organic luminescence devices separated byisolation areas and each having a pair of mutually opposed electrodesand an organic compound layer formed between the paired electrodes,wherein the array includes, in the isolation area, an insulating membercapable of intercepting the external light entering from the exterior ofthe device and preventing reflection of the external light, therebypreventing that the external light is reflected by a wiring providedunder the organic luminescence device and in the isolation area andconnected to the organic luminescence device, and by the surface of theinsulating member in the isolation area.

Also there is provided an organic luminescence device array having aplurality of organic luminescence devices separated by isolation areasand each having a pair of mutually opposed electrodes and an organiccompound layer formed between the paired electrodes, wherein the arrayincludes a wiring connected to the organic luminescence device and aresinous member, provided under the organic luminescence device andbetween the organic luminescence device and the substrate, and theresinous member provided between the substrate and the organicluminescence device is formed as a member for intercepting the externallight entering from the exterior of the device and preventing reflectionof the external light, thereby preventing that the external light isreflected by the wiring provided under the organic luminescence deviceand in the isolation area and connected to the organic luminescencedevice, and by the surface of the insulating member provided between thesubstrate and the organic luminescence device.

Also the aforementioned member for intercepting the external lightentering from the exterior of the device and preventing reflection ofthe external light is formed as a layer on the insulating memberprovided on the wiring and in the isolation area.

Also in the paired electrodes in each organic luminescence device, anelectrode on the substrate side is formed as an electrode capable ofpreventing reflection of the external light entering from the exteriorof the device, while the other electrode is formed as a transparentelectrode, thereby preventing reflection of the external light enteringthe organic luminescence device array from the external environment ineach organic luminescence device area and each isolation area in theorganic luminescence device array.

Also a package, holding in a case an organic luminescence device arraywith anti-reflection for the external light entering from the externalenvironment, does not require a polarizing layer for the purpose ofanti-reflection of the external light, so that a compact and lightpackage of satisfactory visibility of the displayed image for theorganic luminescence device can be provided in a simple and inexpensivemanner.

Fourth Embodiment

An organic luminescence device array according to a fourth embodiment ofthe present invention has a plurality of organic luminescence devicesseparated by isolation areas and each having a pair of mutually opposedelectrodes and an organic compound layer formed between the pairedelectrodes, wherein the array includes a light intercepting member inthe isolation area. FIG. 8 is a schematic view of an organicluminescence device array of the fourth embodiment of the presentinvention, in which provided are a substrate 1, an electrode 2, a holetransporting layer 3, a light emitting layer 4, an electron injectinglayer 5, a transparent electrode 6, a wiring 8 connected to theelectrode 2 of each organic luminescence device, a resinous member 9,and a member 18 for intercepting the external light entering from theexterior of the device and preventing reflection thereof, to constitutean organic luminescence device array of so-called top emission type.

Presence of the member 18 in each isolation area of the organicluminescence devices allows to prevent reflection of the external light,entering from the external environment of the organic luminescencedevice array, by the wiring provided under the organic luminescencedevice and in the isolation area and connected with the organicluminescence device, and the reflection of such external light by suchmember 18 is also prevented, whereby the organic luminescence devicearray provides an increased contrast and improves the visibility of theimage displayed by such device.

In the present embodiment, a known insulating material can be selectedfor the member 18. For example, there can be utilized various blackmatrix materials employed in color filters for a liquid crystal display.Also the organic compound can be a known one, such as Alq3 or α-NPD.Also in the aforementioned organic luminescence device array, theorganic luminescence devices may have light emissions of the same coloror different colors.

Fifth Embodiment

An organic luminescence device array according to a fifth embodiment ofthe present invention has a plurality of organic luminescence devicesseparated by isolation areas and each having a pair of mutually opposedelectrodes and an organic compound layer formed between the pairedelectrodes;

wherein a wiring connected with the organic luminescence device and aresinous member is provided under the organic luminescence device andbetween the organic luminescence device and the substrate, and theresinous member is formed as a member for intercepting the externallight entering from the exterior of the device and preventing reflectionof the external light.

FIG. 9 is a schematic view showing the configuration of an organicluminescence device array of the fifth embodiment of the presentinvention, in which provided are a substrate 1, an electrode 2, a holetransporting layer 3, a light emitting layer 4, an electron injectinglayer 5, a transparent electrode 6, an insulating member 7 provided inan isolation area present between the organic luminescence devices, awiring 8 connected to the electrode 2 of each organic luminescencedevice, and a member 23 for intercepting the external light enteringfrom the exterior of the device and preventing reflection thereof, toconstitute an organic luminescence device array of so-called topemission type.

The resinous member present under each organic luminescence device andbetween the organic luminescence device and the substrate is formed as amember capable of intercepting the external light entering from theexterior of the device and preventing reflection of the external light,whereby the organic luminescence device array provides an increasedcontrast and improves the visibility of the image displayed by suchdevice.

In the present embodiment, a known insulating material can be selectedfor the member 11. For example, there can be utilized various blackmatrix materials employed in color filters for a liquid crystal display.Also the insulating member 7 provided in the isolation area of theorganic luminescence device in the organic luminescence device array canbe a light transmissible member or an opaque member. Also the organiccompound can be a known one, such as Alq3 or α-NPD.

Sixth Embodiment

An organic luminescence device array according to a sixth embodiment ofthe present invention has a plurality of organic luminescence devicesseparated by isolation areas and each having a pair of mutually opposedelectrodes and an organic compound layer formed between the pairedelectrodes;

wherein, on an insulating member provided in the isolation area of theorganic luminescence device, a member is provided for intercepting theexternal light entering from the exterior of the device and preventingreflection of the external light.

FIG. 10 is a schematic view showing the configuration of an organicluminescence device array of the sixth embodiment of the presentinvention, in which provided are a substrate 1, an electrode 2, a holetransporting layer 3, a light emitting layer 4, an electron injectinglayer 5, a transparent electrode 6, an insulating member 7 provided inan isolation area present between the organic luminescence devices, awiring 8 connected to the electrode 2 of each organic luminescencedevice, a resinous member 9, and a member 12 provided in the isolationarea for intercepting the external light entering from the exterior ofthe device and preventing reflection thereof, to constitute an organicluminescence device array of so-called top emission type.

On the insulating member 7 provided in each isolation area of theorganic luminescence devices, a member is provided for intercepting theexternal light entering from the exterior of the device and preventingreflection of the external light, whereby the organic luminescencedevice array provides an increased contrast and improves the visibilityof the image displayed by such device.

In this embodiment, for the member 12, there can be utilized a metallicor resinous black matrix material employed in color filters for a liquidcrystal display, a single-layer or multi-layer material of opticalinterference type, or a material of optical absorption type. Also themember 12 is only required to execute interception and prevention ofreflection of the external light in the isolation area, and it may bepositioned on the surface of the insulating member 7 or above theinsulating member 7 and on the surface of the transparent electrode 6 inthe isolation area. Further, in case the member 12 is a film of opticalinterference type and is provided on the surface of the insulatingmember 7 and below the transparent electrode 6, the prevention ofreflection of the external light can be achieved also by utilizing theinterference with the external light reflected on the surface of thetransparent electrode 6. Also in such case, the insulating member 7provided in each isolation area of the organic luminescence devices inthe organic luminescence device array can be light transmissible oropaque. Also the organic compound can be a known one, such as Alq3 orα-NPD.

Seventh Embodiment

An organic luminescence device array according to a seventh embodimentof the present invention has a plurality of organic luminescence devicesseparated by isolation areas and each having a pair of mutually opposedelectrodes and an organic compound layer formed between the pairedelectrodes, and is provided, in the isolation area, with means whichintercepts the external light entering from the exterior of the deviceand prevents reflection of the external light;

wherein the paired electrodes in each organic luminescence device areconstituted by an electrode positioned at the substrate side and capableof preventing reflection of the external light entering from theexterior of the device and a transparent electrode constituting theother electrode.

FIG. 11 is a schematic view showing the configuration of an organicluminescence device array of the seventh embodiment of the presentinvention, in which provided are a substrate 1, an electrode 13 providedat the side of the substrate in the organic luminescence device andcapable of preventing reflection of the external light entering from theexterior of the device, a hole transporting layer 3, a light emittinglayer 4, an electron injecting layer 5, a transparent electrode 6, aninsulating member 7 provided in an isolation area present between theorganic luminescence devices, a wiring 8 connected to the electrode 13of each organic luminescence device, a resinous member 9, and a member12 provided on the insulating member 7 in the isolation area forintercepting the external light entering from the exterior of the deviceand preventing reflection thereof, to constitute an organic luminescencedevice array of so-called top emission type.

In FIG. 11, a member for preventing reflection of the external light isprovided on the insulating member in the isolation area of the organicluminescence devices, but such means for preventing the reflection ofthe external light is not restrictive, and there may also be applied theconfiguration of the fourth or fifth embodiment.

Since the electrode at the substrate side in each organic luminescencedevice and the isolation area of each organic luminescence device haveanti-reflection means for the external light entering from the exteriorof the device, the organic luminescence device array of this embodimentprovides an increased contrast and improves the visibility of the imagedisplayed by such device.

In the present embodiment, the anti-reflection method for the externallight in the electrode 13 can be an optical absorption type or anoptical interference type.

Eighth Embodiment

An eighth embodiment of the present invention provides an organicluminescence device package holding, in a case, an organic luminescencedevice array having a plurality of organic luminescence devicesseparated by isolation areas and each having a pair of mutually opposedelectrodes and an organic compound layer formed between the pairedelectrodes;

wherein, the electrode at the substrate side in each organicluminescence device and the isolation area of each organic luminescencedevice have anti-reflection means for the external light entering fromthe exterior of the device, whereby the package holding such device inthe case does not require a polarizing layer for the purpose ofanti-reflection for the external light.

FIG. 12 is a view showing the configuration of an organic luminescencedevice array package of the eighth embodiment of the present invention,in which provided are a substrate 1, an electrode 13 provided at theside of the substrate in the organic luminescence device and capable ofpreventing reflection of the external light entering from the exteriorof the device, a hole transporting layer 3, a light emitting layer 4, anelectron injecting layer 5, a transparent electrode 6, an insulatingmember 7 provided in an isolation area present between the organicluminescence devices, a wiring 8 connected to the electrode 13 of eachorganic luminescence device, a resinous member 9, a member 12 providedin the isolation area for intercepting the external light entering fromthe exterior of the device and preventing reflection thereof, and a case14 to constitute an organic luminescence device array of so-called topemission type.

In this embodiment, since the electrode at the substrate side in eachorganic luminescence device and the isolation area of each organicluminescence device have anti-reflection means for the external lightentering from the exterior of the device, the package holding suchdevice in the case does not require a polarizing layer for the purposeof anti-reflection for the external light. Therefore, there can beprovided a thin and light weight package for the organic luminescencedevice array with a high contrast and a high visibility of the displayedimage. Also the manufacturing method is simple and is of a low cost.

In this embodiment, reflection of the external light on the surface ofthe case can be prevented by forming an anti-reflection layer on a faceof the case 14, from which the light emission of the organicluminescence device array is emitted to the external environment. Suchorganic luminescence device array package can further improve thequality of the displayed image.

In any embodiment, the organic layer between the electrodes can beformed by a single layer as explained before or by plural layers such asa three-layer or five-layer structure. Also the organic luminescencedevice of the embodiment may be applied to a display apparatus capableof full-color display, constituted by light-emitting devices of RGBcolors. More specifically, it may be applied to a display unit of adisplay device. The organic luminescence device of any of the embodimentmay be applied, among such display devices, to a pixel unit(light-emitting unit) of a display panel of so-called active matrixdrive, utilizing TFTs.

EXAMPLES

In the following, there will be explained, with reference to theaccompanying drawings, preferred examples of the method for producingthe organic luminescence device of the present invention, but thepresent invention is not limited by such examples.

Example 4

FIG. 8 shows a fourth example of the present invention, in which shownare a substrate 1, an electrode 2, a hole-transporting layer 3, a lightemitting layer 4, an electron injecting layer 5, a transparent electrode6, a wiring 8 connected to the electrode 2 of each organic luminescencedevice, a resinous member 9, and a member 18 for interception andanti-reflection of external light entering from the exterior of thedevice.

On the substrate 1, a chromium film was formed by sputtering andpatterned into a predetermined dimension to form the wiring 8, and thesubstrate 1 was then coated with the resinous member 9. Then a chromiumfilm was formed again on the substrate 1 by sputtering and patternedinto a predetermined dimension to form the electrode 2. Then, in orderto form a high resistance black matrix material in the isolation area ofthe organic luminescence device as the member 18 for interception andanti-reflection of the external light entering from the exterior of thedevice, a commercially available black matrix material was applied onthe substrate 1, then subjected to pattern exposure, development andrinsing to form, in the isolation area, the member 18 for interceptionand anti-reflection for the external light. Then the substrate wassubjected to UV/ozone washing, and a vacuum evaporation apparatus(manufactured by Shinku Kikou Co.) was used to form, on the substrateafter washing, a film of αNPD having a hole transporting property andrepresented by the following chemical formula I

by vacuum evaporation to form the hole-transporting layer 3. The filmformation was conducted under a vacuum of 1.0×10⁻⁶ Torr, and a filmforming rate of 0.2-0.3 nm/sec. Then, on the hole-transporting layer 3,a film of an aluminum chelate (hereinafter called Alq3) represented bythe following chemical formula:

was formed by vacuum evaporation under the same conditions as those inthe formation of the hole-transporting layer 3, thereby obtaining alight-emitting layer 4.

Then, on the light-emitting layer 4, a film of aluminum-lithium as theelectron-injecting layer 5 was formed by vacuum evaporation under thesame conditions as those in the formation of the hole-transporting layer3. Thereafter, on the electron-injecting layer 5, a film of tin indiumoxide (ITO) was formed by sputtering to obtain the transparent electrode6. In this manner an organic luminescence device was prepared on thesubstrate 1, by forming the electrode 2, the hole-transporting layer 3,the light-emitting layer 4, the electron-injecting layer 5, thetransparent electrode 6, the wiring 8, the resinous member 9 and themember 18.

Subsequently, a DC voltage was applied to the organic luminescencedevice under the condition where external light enters the organicluminescence device array from the external environment, in order toinvestigate the light emission characteristics thereof. As a result, itwas confirmed that this organic luminescence device array had a highercontrast and an improved visibility of the displayed image, incomparison with a conventional organic luminescence device array whichis not provided with the member 18 for interception and anti-reflectionof the external light.

Example 5

FIG. 9 shows a fifth example, in which shown are a substrate 1, anelectrode 2, a hole transporting layer 3, a light emitting layer 4, anelectron injecting layer 5, a transparent electrode 6, an insulatingmember 7 provided in the isolation area present between the organicluminescence devices, a wiring 8 connected to the electrode 2 of eachorganic luminescence device, and a member 11 provided under the organicluminescence device and between the organic luminescence device and thesubstrate and serving for interception and anti-reflection of theexternal light entering from the exterior of the device.

Under conditions similar to those in the example 4, a chromium film wasformed by sputtering and patterned into a predetermined dimension toform the wiring 8. Then, in order to form a high resistance black matrixmaterial in the isolation area of the organic luminescence device as themember 11 for interception and anti-reflection of the external lightentering from the exterior of the device, the substrate 1 was coatedwith a commercially available black matrix material, then subjected topattern exposure, development and rinsing to form the member 11 forinterception and anti-reflection for the external light, under theorganic luminescence device and between the organic luminescence deviceand the substrate. Then a chromium film as the electrode 2 was formedagain on the substrate 1 by sputtering and patterned into apredetermined dimension. Thereafter, in order to form the insulatingmember 7 in the isolation area of the organic luminescence device, thesubstrate 1 was coated with a commercial photoresist followed by patternexposure, development and rinsing thereby forming the insulating member7 in the isolation area. Then the substrate was subjected to UV/ozonewashing, and a film of αNPD was formed as the hole-transporting layer 3,and a film of Alq3 was formed as the light-emitting layer 4. Then, afilm of aluminum-lithium was formed as the electron-injecting layer 5.Thereafter, on the electron-injecting layer 5, a film of tin indiumoxide (ITO) was formed by sputtering to obtain the transparent electrode6, thereby completing an organic luminescence device.

Subsequently, a DC voltage was applied to the organic luminescencedevice under the condition where external light enters the organicluminescence device array from the external environment, in order toinvestigate the light emission characteristics thereof. As a result, itwas confirmed that this organic luminescence device array had a highercontrast and an improved visibility of the displayed image, incomparison with a conventional organic luminescence device array whichis not provided with the member 11 for interception and anti-reflectionof the external light.

Example 6

FIG. 10 shows a sixth example, in which shown are a substrate 1, anelectrode 2, a hole transporting layer 3, a light emitting layer 4, anelectron injecting layer 5, a transparent electrode 6, an insulatingmember 7 provided in the isolation area present between the organicluminescence devices, a wiring 8 connected to the electrode 2 of eachorganic luminescence device, a resinous member 9, and a member 12provided on the insulating member 7 in each isolation area forinterception and anti-reflection of the external light entering from theexterior of the device.

Under conditions similar to those in the example 4, a chromium film wasformed by sputtering and patterned into a predetermined dimension toform the wiring 8. Then, the substrate 1 was coated with the resinousmember 9. Then a chromium film was formed again on the substrate 1 bysputtering and was patterned into a predetermined dimension to form theelectrode 2. Thereafter, in order to form the insulating member 7 in theisolation area of the organic luminescence device, the substrate wascoated with a commercial photoresist followed by pattern exposure,development and rinsing thereby forming the insulating member 7 in theisolation area. Then the member 12, for interception and anti-reflectionfor the external light entering from the exterior of the device byoptical interference, was formed on the insulating member 7. The member12 was so designed as to extinguish, by optical interference, also thereflection of the external light on the surface of the transparentelectrode 6 to be formed later on the member 12. Then the substrate wassubjected to UV/ozone washing, and a film of αNPD was formed as thehole-transporting layer 3, and a film of Alq3 was formed as thelight-emitting layer 4. Then, a film of aluminum-lithium was formed asthe electron-injecting layer 5. Thereafter, on the electron-injectinglayer 5, a film of tin indium oxide (ITO) was formed by sputtering toobtain the transparent electrode 6, thereby completing an organicluminescence device array.

Subsequently, a DC voltage was applied to the organic luminescencedevice array in a situation where external light enters the organicluminescence device array from the external environment, in order toinvestigate the light emission characteristics thereof. As a result, itwas confirmed that this organic luminescence device array had a highercontrast and an improved visibility of the displayed image, incomparison with a conventional organic luminescence device array whichis not provided with the member 12 for interception and anti-reflectionof the external light.

Example 7

FIG. 11 shows a seventh example, in which shown are a substrate 1, anelectrode 13 provided at the substrate side of the organic luminescencedevice and capable of anti-reflection of the external light enteringfrom the exterior of the device, a hole transporting layer 3, a lightemitting layer 4, an electron injecting layer 5, a transparent electrode6, an insulating member 7 provided in the isolation area present betweenthe organic luminescence devices, a wiring 8 connected to the electrode13 of each organic luminescence device, a resinous member 9, and amember 12 provided on the insulating member 7 in the isolation area forinterception and anti-reflection of the external light entering from theexterior of the device.

The electrode 13 prevents, by optical absorption or opticalinterference, the reflection of the light entering the device from theexterior. For example, it may be formed by an electrode called BlackLayer, capable of intercepting the external light and preventingreflection thereof by optical interference.

Under conditions similar to those in the example 4, a chromium film wasformed by sputtering and patterned into a predetermined dimension toform the wiring 8. Then, the substrate 1 was coated with the resinousmember 9. Then a chromium film, a indium tin oxide (ITO) film and achromium film were formed again on the substrate 1 by sputtering andwere patterned into a predetermined dimension to form the electrode 13,constituted by three layers of chromium-ITO-chromium and so-called BlackLayer technology utilizing optical interference. Thereafter, in order toform the insulating member 7 in the isolation area of the organicluminescence device, the substrate 1 was coated with a commercialphotoresist followed by pattern exposure, development and rinsingthereby forming the insulating member 7 in the isolation area. Then themember 12, for interception and anti-reflection for the external lightentering from the exterior of the device by optical interference, wasformed on the insulating member 7. The member 12 was so designed as toextinguish, by optical interference, also the reflection of the externallight on the surface of the transparent electrode 6 to be formed lateron the member 12. Then the substrate was subjected to UV/ozone washing,and a film of αNPD was formed as the hole-transporting layer 3, and afilm of Alq3 was formed as the light-emitting layer 4. Then, a film ofaluminum-lithium was formed as the electron-injecting layer 5.Thereafter, on the electron-injecting layer 5, a film of tin indiumoxide (ITO) was formed by sputtering to obtain the transparent electrode6, thereby completing an organic luminescence device array.

Subsequently, a DC voltage was applied to the organic luminescencedevice array under the condition where external light enters the organicluminescence device array from the external environment, in order toinvestigate the light emission characteristics thereof. As a result, itwas confirmed that this organic luminescence device array had a highercontrast and an improved visibility of the displayed image, incomparison with a conventional organic luminescence device array whichis not provided with the electrode 13 for interception andanti-reflection of the external light and the member 12 for interceptionand anti-reflection of the external light.

Example 8

FIG. 12 shows an eighth example, in which shown are a substrate 1, anelectrode 13 provided at the substrate side of the organic luminescencedevice and capable of anti-reflection of the external light enteringfrom the exterior of the device, a hole transporting layer 3, a lightemitting layer 4, an electron injecting layer 5, a transparent electrode6, an insulating member 7 provided in the isolation area present betweenthe organic luminescence devices, a wiring 8 connected to the electrode13 of each organic luminescence device, a resinous member 9, a member 12provided on the insulating member 7 in the isolation area forinterception and anti-reflection of the external light entering from theexterior of the device, and a case 14.

Under conditions similar to those in the example 4, a chromium film wasformed by sputtering and patterned into a predetermined dimension toform the wiring 8. Then, the substrate 1 was coated with the resinousmember 9. Then a chromium film, a indium tin oxide (ITO) film and achromium film were formed again on the substrate 1 by sputtering andwere patterned into a predetermined dimension to form the electrode 13,constituted by three layers of chromium-ITO-chromium and so-called BlackLayer technology utilizing optical interference. Thereafter, in order toform the insulating member 7 in the isolation area of the organicluminescence device, the substrate 1 was coated with a commercialphotoresist followed by pattern exposure, development and rinsingthereby forming the insulating member 7 in the isolation area. Then themember 12, for interception and anti-reflection for the external lightentering from the exterior of the device by optical interference, wasformed on the insulating member 7. The member 12 was so designed as toextinguish, by optical interference, also the reflection of the externallight on the surface of the transparent electrode 6 to be formed lateron the member 12. Then the substrate was subjected to UV/ozone washing,and a film of αNPD was formed as the hole-transporting layer 3, and afilm of Alq3 was formed as the light-emitting layer 4. Then, a film ofaluminum-lithium was formed as the electron-injecting layer 5.Thereafter, on the electron-injecting layer 5, a film of tin indiumoxide (ITO) was formed by sputtering to obtain the transparent electrode6, thereby completing an organic luminescence device array.

Then a glass case 14 was placed on the upper surface of the substrate soas to hold the organic luminescence device array, thereby obtaining anorganic luminescence device array package. In such organic luminescencedevice array package, on a surface thereof where the light is emittedfrom the case 14, an anti-reflection layer was formed by alternatelylaminating SiO₂ and TiO₂ thin films by sputtering, thereby preventingthe reflection of the external light on the case surface.

Subsequently, a DC voltage was applied to the organic luminescencedevice array under the condition where external light enters the organicluminescence device array from the external environment, in order toinvestigate the light emission characteristics thereof. As a result, itwas confirmed that the visibility of the image displayed by this organicluminescence device array package was comparable to that in aconventional organic luminescence device array package which is providedwith a polarizing layer on the package surface in order to preventreflection of the external light entering the device from the externalenvironment. Also, because of the absence of the polarizing layer, theorganic luminescence device array package of the present invention wasthinner and lighter than the conventional package, and was simpler andmore inexpensive in the manufacture.

The present invention, by forming means for avoiding the influence ofthe external light, entering the organic luminescence device array fromthe external environment, allows to provide an organic luminescencedevice array with a high contrast and an improved visibility of thedisplayed image. There can also be provided an organic luminescencedevice package which is thin, light, simple in manufacture andinexpensive in cost.

In the following there will be explained ninth to thirteenth embodimentsand ninth to thirteenth examples.

These embodiments and examples provide an organic luminescence package,formed by packaging an organic luminescence device, having at least apair of mutually opposed electrodes and an organic compound layer formedbetween the paired electrodes, in a case, thereby protecting the organicluminescence layer from moisture and atmosphere in the externalenvironment.

Thus, there is provided an organic luminescence device package of whichthe case is provided with an anti-reflection film on an entrance facefor the light emitted from the organic luminescent layer (the entranceface means a face opposed to the luminescence device, among the facesdefining the internal space of the case, on the light-emitting side; theexpression “entrance face” on such light-emitting side being used forthe purpose of distinguishing from a face on the external surface of thecase, separated from the entrance face by the thickness of the caseitself and thus constituting the rear surface of the entrance face).

Also the embodiments provide an organic luminescence device packagefurther having an anti-reflection layer on the entrance face of thelight emitted from the organic luminescence layer and on the transparentelectrode of the organic luminescence layer.

Also the embodiments provide an organic luminescence device package inwhich, in a space contained in the case, a light transmissible resin isfilled in a portion other than the organic luminescence device.

Also the embodiments provide an organic luminescence device packagefurther having an anti-reflection layer, in the aforementioned case, onthe entrance face of the light emitted from the organic luminescencelayer, on the transparent electrode of the organic luminescence layer,and also, in the aforementioned case, on a face which is opposed to theentrance face of the light emitted from the organic luminescence layerand from which the light is emitted to the external environment.

Ninth Embodiment

In a ninth embodiment of the present invention, an anti-reflection layeris provided on a transparent electrode 6 constituting a light-emittingelectrode. FIG. 13 schematically shows a layered structure of an organicluminescence device package of the ninth embodiment of the presentinvention, in which shown are a substrate 1 (so-called base material,which can be a flexible member such as PET or an undeformable membersuch as glass and which can be light transmissible or opaque), anelectrode 2, a hole transporting layer 3, a light emitting layer 4, anelectron injecting layer 5, a transparent electrode 6, a case 14, and ananti-reflection layer 17 to constitute an organic luminescence device ofso-called top emission type.

The organic luminescence device is constituted by the electrode 2 andthe organic layer or hole-transporting layer 3, the light-emitting layer4, the electron-injecting layer 5 and the transparent electrode 6.

The organic luminescence device is formed on the substrate, and iscovered by the case 14 on the substrate, thus being held in an holdingspace of the case 14.

The light is emitted from the organic luminescence device and to theexterior of the organic luminescence device package through the case 14which is a transparent member on an upper side of the drawing.

In the case, the side through which the light is emitted to the exterioris a light-emitting side. As shown in the drawing, the case isconstituted by the light-emitting side and the pillar side forsupporting the light-emitting side on the substrate.

In the light-emitting side, a face closer to the organic luminescencedevice is a light-emitting face, which constitutes a space holding theorganic luminescence device. On the other hand, in the light-emittingside of the case 14, a face at the outer surface of the organicluminescence device package can be called the rear face of thelight-emitting face.

The anti-reflection layer 17, provided in the holding space, preventsthat the light emitted from the light-emitting layer 4 is reflected atthe interface between an unrepresented atmospheric gas in the package(in the holding space) and the entrance face (light-emitting face) ofthe case 14, whereby the light-emitting efficiency of the device can beimproved.

In this embodiment, the anti-reflection layer can be advantageously of asingle layer type or a multi layer type. The organic compound can be aknown one such as Alq3 or α-NPD.

Also in this embodiment, the organic layer between the electrodes can beformed by a single layer, or by plural layers such as a three-layer orfive-layer structure. Also the organic luminescence device of theembodiment may be applied to a display apparatus capable of full-colordisplay, constituted by light-emitting devices of RGB colors. Morespecifically, it may be applied to a display unit of a display device.The organic luminescence device of the embodiment may be applied, amongsuch display devices, to a pixel unit (light-emitting unit) of a displaypanel of so-called active matrix drive, utilizing TFTs.

Tenth Embodiment

An organic luminescence device package of a tenth embodiment of thepresent invention is featured by having an anti-reflection layer in twolocations, namely on the light-emitting face and on the transparentelectrode of the organic luminescence device. In other aspects it is thesame as the ninth embodiment.

More specifically, in an organic luminescence device package, formed bypackaging an organic luminescence device, having at least a pair ofmutually opposed electrodes and an organic compound layer formed betweenthe paired electrodes, in a case, thereby protecting the organicluminescence layer from moisture and atmosphere in the externalenvironment, an anti-reflection layer is provided in two locations onthe entrance face of the light from the organic luminescence layer andon the transparent electrode of the organic luminescence layer.

FIG. 14 schematically shows a layered structure of an organicluminescence device package of the tenth embodiment of the presentinvention, in which shown are a substrate 1, an electrode 2, a holetransporting layer 3, a light emitting layer 4, an electron injectinglayer 5, a transparent electrode 6, a case 14, an anti-reflection layer17 provided on the light entrance face of the case, and ananti-reflection layer 19 provided on the transparent electrode of theorganic luminescence device, to constitute an organic luminescencedevice of so-called top emission type.

The anti-reflection layers in these two locations prevent the reflectionof the light emitted from the light-emitting layer 4 at the interfacebetween the atmospheric gas in the package and the entrance face of thecase 14 and the interface between the atmospheric gas in the package andthe transparent electrode 6, whereby the light-emitting efficiency ofthe device can be improved.

In the present embodiment, the anti-reflection layer can beadvantageously of a single layer type or a multi layer type. Theanti-reflection layer provided on the case 14 and that provided on thetransparent electrode may be of the same material or of differentmaterials.

Eleventh Embodiment

An organic luminescence device package of an eleventh embodiment of thepresent invention is featured in that a holding space of the case whichis filled with a light transmissible resin, and that the lighttransmissible resin has a refractive index between those of a materialconstituting the case and of the transparent electrode. In other aspectsit is the same as the ninth or tenth embodiment.

More specifically, in an organic luminescence device package, formed bypackaging an organic luminescence device, having at least a pair ofmutually opposed electrodes and an organic compound layer formed betweenthe paired electrodes, in a case, thereby protecting the organicluminescence layer from moisture and atmosphere in the externalenvironment, a light transmissible resin is filled in a space containedin the case and in a portion other than the organic luminescence deviceand such light transmissible resin is selected from a material of arefractive index between those of a material constituting the case andthe transparent electrode.

FIG. 15 schematically shows a layered structure of an organicluminescence device package of an eleventh embodiment of the presentinvention, in which shown are a substrate 1, an electrode 2, a holetransporting layer 3, a light emitting layer 4, an electron injectinglayer 5, a transparent electrode 6, a case 14, and a light transmissibleresin 20 filled in a space contained in the case and in a portion otherthan the organic luminescence device, to constitute an organicluminescence device of so-called top emission type.

Since the space other than the organic luminescence device within theholding space of the case is filled with the light transmissible resinof a refractive index positioned between those of the materialconstituting the case and of the transparent electrode, there can bereduced the interfacial reflections of the light emitted from thelight-emitting layer 4 in emerging from the transparent electrode 6 andin entering the case 14, whereby the light-emitting efficiency of thedevice can be improved.

In the present embodiment, the light transmissible resin can be knownone, such as epoxy or acrylic light transmissible resin.

Twelfth Embodiment

An organic luminescence device package of a twelfth embodiment of thepresent invention is featured by having an anti-reflection layer inthree locations, namely on the light-emitting face of the case, on thetransparent electrode of the organic luminescence device, and on therear face of the light-emitting face at the light-emitting side of thecase. In other aspects it is same as the ninth to eleventh embodiments.

More specifically, in an organic luminescence device package, formed bypackaging an organic luminescence device, having at least a pair ofmutually opposed electrodes and an organic compound layer formed betweenthe paired electrodes, in a case, thereby protecting the organicluminescence layer from moisture and atmosphere in the externalenvironment, an anti-reflection layer is provided in three locations onthe entrance face of the light from the organic luminescence layer, onthe transparent electrode of the organic luminescence layer, and on theemerging face of the light to the external environment in the case.

FIG. 16 schematically shows the twelfth embodiment of the presentinvention, in which shown are a substrate 1, an electrode 2, a holetransporting layer 3, a light emitting layer 4, an electron injectinglayer 5, a transparent electrode 6, a case 14, an anti-reflection layer17 provided on the light entrance face of the case, an anti-reflectionlayer 19 provided on the transparent electrode of the organicluminescence device, and an anti-reflection layer 21 provided on anemerging face of the case 14 for the light to the external environment,to constitute an organic luminescence device of so-called top emissiontype.

The anti-reflection layers in these three locations prevent thereflection of the light emitted from the light-emitting layer 4 at theinterface between the atmospheric gas in the package and the entranceface of the case 14, at the interface between the atmospheric gas in thepackage and the transparent electrode 6, and the reflection of theexternal light entering the package from the external environment at thelight-emerging face of the case, whereby the light-emitting efficiencyof the device and the contrast of light emission can be improved.

The anti-reflection layers of three locations, namely those provided ontwo locations of the case 14 and that provided on the transparentelectrode, may be of the same material or of different materials.

The light-emitting efficiency of the device in the foregoing embodimentscan be estimated as follows, in the configurations shown in FIGS. 13 to15.

Light reflection becomes larger and light transmission is lowered at aninterface where the constituting materials thereof show a largerdifference in the refractive indexes. More specifically, at theinterface between the transparent electrode 6 and the space contained inthe case, for an ITO transparent electrode with a refractive indexn6=2.0 and a space of nitrogen or air with a refractive index nk=1, thereflectance is given by (n6−nk)²/(n6+nk)² and corresponds to areflection loss of about 11%. Also at the interface of the upper/lowerface of the case 14 and the space, for the case 14 with a refractiveindex n7=1.45, the reflectance is given by (n7−nk)²/(n7+nk)² andcorresponds to a reflection loss of about 4%. Thus, even disregardingthe reflection losses on other interfaces, the light emission is lost byabout 19% in total. Thus, for improving the light-emission efficiency,it is necessary to suppress the reflection loss and to improve thetransmittance of light emitted from the light emitting layer 4 to theupper space through the case 14.

An anti-reflection film is effective for suppressing the reflectionloss. A known anti-reflection film utilizes a transparent materialhaving a large refractive index such as ZnS, CeO₂ or TiO₂ and a materialhaving a small refractive index such as LiF, CaF₂, MgF₂ or SiO₂ and isformed by alternately laminating the material having a larger refractiveindex and the material having a smaller refractive index (with mutuallydifferent refractive indexes) with each thickness obtained by dividing adesign wavelength with (4×refractive index of material). In suchconfiguration, it is necessary to employ a material having a refractiveindex smaller than that of a material constituting the interface, as thematerial of the smaller refractive index in the anti-reflection film.For example, a three-pair anti-reflection film employing NaF or LiF(smaller refractive index) and TiO₂ (larger refractive index) (forexample, case surface/LiF/TiO₂/LiF/TiO₂/LiF/TiO₂) allows to reduce theabove-mentioned interfacial reflection loss to 1/10 or less. In case theanti-reflection film 15 has a single layer structure, there is selecteda material having a refractive index lower than that of the materialconstituting the layer of which reflection loss is to be suppressed.

In the configuration shown in FIG. 15, the presence of the lighttransmissible resin 20 (for example with a refractive index n10=1.65)can reduce the reflection loss of the emitted light at the case 14. Thereflectance is represented by (n10−n7)²/(n10+n7)² which corresponds to areflection of about 1%, which is about ¼ in comparison with a casewithout the light transmissible resin 20. Also the emitted light isreflected upon emerging from the transparent electrode 6 to the space ofthe case 14, thus returning to the device. The reflectance isrepresented by (n6−nk)²/(n6+nk)² corresponding to a reflection of about11%. This reflected light is reflected by the electrode 2 and emittedagain, but, unless the electrode 2 has a high reflectance, it isabsorbed by the electrode 2 to result in a loss. Also in this case, thepresence of the light transmissible resin 20 (for example with arefractive index n10=1.65) reduces the reflection at the interface withthe transparent electrode 6, represented by (n6−nk)²/(n6+nk)², to about0.9%. In this manner, the presence of the light transmissible resin 20significantly reduces the interfacial reflections.

A contrast of a device can be evaluated by the following formula:C=1+B/(γ×A)wherein C is a contrast evaluation value, A is luminosity (ft-L) ofexternal light, B is luminosity (ft-L) of the device, and γ isreflectance (%) of the entire device.

It is therefore necessary to observe the device in a darker place (A)with a lowered reflectance (γ) and with a higher luminosity (B).

In practice, a difficulty may arise in an outdoor use. The luminosity ofthe external light may become several to ten and several times of thatof the device.

The reflection loss, which lowers the transmission, also reduces thecontrast. In the absence of the aforementioned anti-reflection film,because of a reflection of the external light of about 19%, the contrastvalue becomes 10 or less even under the external light of a luminositycomparable to that of the device. On the other hand, the presence of theaforementioned anti-reflection film, capable of reducing the reflectionof the external light to about 1%, can provide a satisfactory contrastvalue close to 100. However, in case the electrode 2 has a highreflectance (for example 20% or higher), a sufficient improvement incontrast cannot be attained by the reflection of the external light bythe electrode 2.

Thirteenth Embodiment

An organic luminescence device package of a thirteenth embodiment of thepresent invention is featured in that, in the aforementioned mutuallyopposed electrodes, an electrode provided at the substrate side isformed-by an electrode capable of interception and anti-reflection ofthe external light while the other electrode is formed as a transparentelectrode. In other aspects it is the same as the ninth or twelfthembodiment.

FIG. 17 shows a thirteenth embodiment of the present invention, showingan example of applying the configuration of the thirteenth embodiment tothe configuration of the twelfth embodiment of the present invention.The thirteenth embodiment of the present invention is advantageouslyapplicable to any of the ninth to eleventh embodiments.

In FIG. 17, there are shown a substrate 1, an electrode 24 capable ofinterception and anti-reflection for the external light, a holetransporting layer 3, a light emitting layer 4, an electron injectinglayer 5, a transparent electrode 6, a case 14, an anti-reflection layer17 provided on the entrance face of the case 14 for the light from thelight-emitting layer 4, an anti-reflection layer 19 provided on thetransparent electrode 6, and an anti-reflection layer 21 provided on anemerging face of the case 14 for the light to the external environment,to constitute an organic luminescence device of so-called top emissiontype.

In the aforementioned organic luminescence device, the electrodeprovided at the substrate side is formed as an electrode capable ofinterception and anti-reflection of the external light, therebypreventing the reflection of the external light at the electrodeprovided at the substrate side, thus improving the contrast of the lightemission.

In the electrode provided at the substrate side, the interception andanti-reflection for the external light may be achieved by an opticalabsorption system or an optical interference system.

The anti-reflection layers of three locations, namely those provided ontwo locations of the case 14 and that provided on the transparentelectrode, may be of the same material or of different materials.

EXAMPLES

In the following, there will be explained, with reference to theaccompanying drawings, preferred examples of the method for producingthe organic luminescence device of the present invention, but thepresent invention is not limited by such examples.

Example 9

FIG. 13 shows a ninth example of the present invention, in which shownare a substrate 1, an electrode 2, a hole transporting layer 3, a lightemitting layer 4, an electron injecting layer 5, a transparent electrode6, a case 14, and an anti-reflection layer 17.

On the substrate 1, a chromium film was formed by sputtering to obtainthe electrode 2. Then the substrate was subjected to ultrasonic rinsingin succession with acetone and isopropyl alcohol (IPA), then washed byboiling in IPA and dried. It was further subjected to UV/ozone washing.

Then a vacuum evaporation apparatus (manufactured by Shinku Kikou Co.)was used to form, on the substrate after washing, a film of αNPD havinga hole transporting property and represented by the following chemicalformula I

by vacuum evaporation to form the hole-transporting layer 3. The filmformation was conducted under a vacuum of 1.0×10⁻⁶ Torr, and a filmforming rate of 0.2-0.3 nm/sec. Then, on the hole-transporting layer 3,a film of an aluminum chelate (hereinafter called Alq3) represented bythe following chemical formula:

was formed by vacuum evaporation under the same conditions as those inthe formation of the hole-transporting layer 3, thereby obtaining alight-emitting layer 4. Then, on the light-emitting layer 4, a film ofaluminum-lithium as the electron-injecting layer 5 was formed by vacuumevaporation under the same conditions as those in the formation of thehole-transporting layer 3. Thereafter, on the electron-injecting layer5, a film of tin indium oxide (ITO) was formed by sputtering to obtainthe transparent electrode 6. In this manner an organic luminescencedevice was prepared on the substrate 1, by forming the electrode 2, thehole-transporting layer 3, the light-emitting layer 4, theelectron-injecting layer 5, the transparent electrode 6, and theanti-reflection layer.

Then, on an entrance face of a glass case 14, receiving the lightemission from the light-emitting layer 4, the anti-reflection layer 17was formed by alternately laminating SiO₂ and TiO₂ thin films bysputtering.

Then the case having the anti-reflection layer 17 was placed on theupper surface of the substrate so as to hold the organic luminescencedevice array, thereby obtaining an organic luminescence device package.

Subsequently, a DC voltage was applied to the organic luminescencedevice package, in order to investigate the light emissioncharacteristics thereof. As a result, it was confirmed that thelight-emitting efficiency was improved in comparison with an organicluminescence device package without the anti-reflection layer 17.

Example 10

FIG. 14 shows a tenth example, in which shown are a substrate 1, anelectrode 2, a hole transporting layer 3, a light emitting layer 4, anelectron injecting layer 5, a transparent electrode 6, a case 14, ananti-reflection layer 17, and an anti-reflection layer 19 provided onthe transparent electrode 6 of the organic luminescence device.

Under conditions similar to those in the example 9, a chromium filmconstituting the electrode 2 was formed by sputtering, then a film ofαNPD was formed as the hole-transporting layer 3, and a film of Alq3 wasformed as the light-emitting layer 4. Then, a film of aluminum-lithiumwas formed as the electron-injecting layer 5. Thereafter, on theelectron-injecting-layer 5, a film of indium tin oxide (ITO) was formedby sputtering to obtain the transparent electrode 6. Then, on thetransparent electrode 6, thin films of SiO₂ and TiO₂ were alternatelylaminated by sputtering to form the anti-reflection film, therebycompleting the organic luminescence device.

Then the glass case, having the anti-reflection layer 17 on the entranceface for the light emission from the light-emitting layer 4, was placedon the upper surface of the substrate so as to hold the organicluminescence device, thereby obtaining an organic luminescence devicepackage.

Subsequently, a DC voltage was applied to the organic luminescencedevice package, in order to investigate the light emissioncharacteristics thereof. As a result, it was confirmed that thelight-emitting efficiency was improved in comparison with an organicluminescence device package without the anti-reflection layers 17 and19.

Example 11

FIG. 15 shows an eleventh example, in which shown are a substrate 1, anelectrode 2, a hole transporting layer 3, a light emitting layer 4, anelectron injecting layer 5, a transparent electrode 6, a case 14, and alight transmissible resin 20.

Under conditions similar to those in the example 9, a chromium filmconstituting the electrode 2 was formed by sputtering, then a film ofαNPD was formed as the hole-transporting layer 3, and a film of Alq3 wasformed as the light-emitting layer 4. Then, a film of aluminum-lithiumwas formed as the electron-injecting layer 5. Thereafter, on theelectron-injecting layer 5, a film of indium tin oxide (ITO) was formedby sputtering to obtain the transparent electrode 6. Then the glasscase, having the anti-reflection layer 17 on the entrance face for thelight emission from the light-emitting layer 4, was placed on the uppersurface of the substrate so as to hold the organic luminescence device,thereby obtaining an organic luminescence-device package.

Subsequently, a DC voltage was applied to the organic luminescencedevice package, in order to investigate the light emissioncharacteristics thereof. As a result, it was confirmed that thelight-emitting efficiency was improved in comparison with a conventionalorganic luminescence device package in which the space other than theorganic luminescence device was not filled with the light transmissibleresin.

Example 12

FIG. 16 shows a twelfth example, in which shown are a substrate 1, anelectrode 2, a hole transporting layer 3, a light emitting layer 4, anelectron injecting layer 5, a transparent electrode 6, a case 14, ananti-reflection layer 17 provided on the entrance face of the case 14for the light from the light-emitting layer 4, an anti-reflection layer19 provided on the transparent electrode 6, and an anti-reflection layer21 provided on an exit face of the case 14 for the light emerging to theexternal environment.

Under conditions similar to those in the example 9, a chromium filmconstituting the electrode 2 was formed by sputtering, then a film ofαNPD was formed as the hole-transporting layer 3, and a film of Alq3 wasformed as the light-emitting layer 4. Then, a film of aluminum-lithiumwas formed as the electron-injecting layer 5. Thereafter, on theelectron-injecting layer 5, a film of indium tin oxide (ITO) was formedby sputtering to obtain the transparent electrode 6. Then, on thetransparent electrode 6, thin films of SiO₂ and TiO₂ were alternatelylaminated by sputtering to form the anti-reflection film, therebycompleting the organic luminescence device.

Then the glass case, having the anti-reflection layers 17 and 19 formedby alternately laminating SiO₂ and TiO₂ thin films by sputtering on theentrance face for the light emitted from the light-emitting layer 4 andon the exit face for the light emission from the case to the externalenvironment, was placed on the upper surface of the substrate so as tohold the organic luminescence device, thereby obtaining an organicluminescence device package.

Subsequently, a DC voltage was applied to the organic luminescencedevice package, in order to investigate the light emissioncharacteristics thereof. As a result, it was confirmed that thelight-emitting efficiency and the contrast of the organic luminescencedevice were significantly improved in comparison with an organicluminescence device package without the anti-reflection layers 17, 19and 21.

Example 13

FIG. 17 shows a thirteenth example, in which the configuration of thethirteenth example is applied to the configuration of the twelfthexample of the present invention. The thirteenth example of the presentinvention is advantageously applicable to any of the ninth to eleventhexamples.

In FIG. 17, there are shown a substrate 1, an electrode 24 capable ofinterception and anti-reflection for the external light, a holetransporting layer 3, a light emitting layer 4, an electron injectinglayer 5, a transparent electrode 6, a case 14, an anti-reflection layer17 provided on the entrance face of the case 14 for the light from thelight-emitting layer 4, an anti-reflection layer 19 provided on thetransparent electrode 6, and an anti-reflection layer 21 provided on anemerging face of the case 14 for the light to the external environment.

The electrode 24 with interception and anti-reflection of the externallight prevents, by optical absorption or optical interference, thereflection of the light entering the device from the exterior. Forexample, it may be formed by an electrode called Black Layer, capable ofintercepting the external light and preventing reflection thereof byoptical interference.

Under conditions similar to those in the example 1, a chromium film, aindium tin oxide (ITO) film and a chromium film were formed on thesubstrate 1 by sputtering and were patterned into a predetermineddimension to form the electrode 24, constituted by three layers ofchromium-ITO-chromium and so-called Black Layer technology utilizingoptical interference. Thereafter, the substrate was subjected toUV/ozone washing, and a film of αNPD was formed as the hole-transportinglayer 3, and a film of Alq3 was formed as the light-emitting layer 4.Then, a film of aluminum-lithium was formed as the electron-injectinglayer 5. Thereafter, on the electron-injecting layer 5, a film of indiumtin oxide (ITO) was formed by sputtering to obtain the transparentelectrode 6. Then, on the transparent electrode 6, SiO₂ and TiO₂ thinfilms were alternately laminated by sputtering to form theanti-reflection layer 9 thereby completing an organic luminescencedevice.

Then the glass case, having the anti-reflection layers 17 and 9 formedby alternately laminating SiO₂ and TiO₂ thin films by sputtering on theentrance face for the light emitted from the light-emitting layer 4 andon the exit face for the light emission from the case 14 to the externalenvironment, was placed on the upper surface of the substrate so as tohold the organic luminescence device, thereby obtaining an organicluminescence device package.

Subsequently, a DC voltage was applied to the organic luminescencedevice package, in order to investigate the light emissioncharacteristics thereof. As a result, it was confirmed that thelight-emitting efficiency and the contrast of the organic luminescencedevice were significantly improved in comparison with a conventionalorganic luminescence device package without the anti-reflection layers17, 19 and 21, and without the electrode 24 with interception andanti-reflection of the external light.

The anti-reflection layer of the present invention allows to provide anorganic luminescence device of a high efficiency and an organicluminescence device of a satisfactory contrast.

As explained by the first to thirteenth embodiments and the first tothirteenth examples in the foregoing, the presence of theanti-reflection layer allows to provide an organic luminescence device,an organic luminescence device array and an organic luminescence devicepackage of a high efficiency and a satisfactory contrast.

1. A top-emission organic luminescence device having a light-emittinglayer comprising: (a) a pair of mutually opposed electrodes, whereinsaid pair of electrodes are a first electrode provided on a substrateand a transparent second electrode disposed farther from said substratethan said first electrode; (b) an anti-reflection layer provided on saidtransparent second electrode and in contact therewith at an interfacetherebetween, wherein the anti-reflection layer has a refractive indexless than the transparent second electrode, and a side of theanti-reflection layer opposite to the interface is in contact with anexternal environment, and the thickness of said anti-reflection layersatisfies the following equation:d=λ/4n where d represents the thickness of said anti-reflection layer, λrepresents a wavelength of light emitted from the light-emitting layer,and n represents the refractive index of said anti-reflection layer and(c) an organic light-emitting layer formed between said pair ofelectrodes, wherein the reflection of the light emitted from thelight-emitting layer at the interface of the side of the transparentsecond electrode opposite to the organic light emitting layer isprevented by said anti-reflection layer.
 2. The organic luminescencedevice according to claim 1, wherein said first electrode provided onthe substrate side is capable of intercepting external light andpreventing reflection of external light.
 3. The organic luminescencedevice according to claim 1, wherein the anti-reflection layer is asingle layer.
 4. The organic luminescence device according to claim 1,wherein the anti-reflection layer is multi-layers.
 5. The top-emissionorganic luminescence device according to claim 1, wherein saidtransparent second electrode is composed of indium tin oxide.
 6. Atop-emission organic luminescence device comprising: (a) a pair ofmutually opposed electrodes, wherein said pair of electrodes are a firstelectrode provided on a substrate and a transparent second electrode,disposed farther from the substrate than said first electrode; (b) amoisture prevention layer provided on said transparent second electrode;(c) an anti-reflection layer provided on said moisture prevention layerforming an interface therebetween, wherein a side of the anti-reflectionlayer opposite to the interface is in contact with an externalenvironment, and the thickness of said anti-reflection layer satisfiesthe following equation:d=λ/4n where d represents the thickness of said anti-reflection layer, λrepresents a wavelength of light emitted from the light-emitting layer,and n represents the refractive index of said anti-reflection layer; and(d) a light-emitting organic layer formed between said pair ofelectrodes, whereby emitted light is transmitted through the transparentsecond electrode to the external environment; wherein the reflection ofthe light emitted from the light-emitting layer at the interface of theside of the moisture prevention layer opposite to the transparent secondelectrode is prevented by said anti-reflection layer.
 7. The organicluminescence device according to claim 6, wherein said first electrodeprovided on the substrate side is capable of intercepting external lightand preventing reflection of external light.
 8. The organic luminescencedevice according to claim 6, wherein the anti-reflection layer has arefractive index less than the moisture prevention layer.
 9. The organicluminescence device according to claim 6, wherein the anti-reflectionlayer is a single layer.
 10. The organic luminescence device e accordingto claim 6, wherein the anti-reflection layer is multi-layers.
 11. Thetop-emission organic luminescence device according to claim 6, whereinsaid transparent second electrode is composed of indium tin oxide. 12.The top-emission organic luminescence device according to claim 6,wherein said moisture prevention layer is composed of SiN.
 13. Atop-emission organic luminescence device comprising in this order: (a) asubstrate; (b) a first electrode; (c) a light-emitting organic layer;(d) a transparent second electrode; (e) a layer of silicon nitride; (f)a layer of silicon oxide provided on the layer of silicon nitride and incontact therewith at an interface therebetween, wherein a side of thelayer of silicon oxide opposite to the interface is in contact with anexternal environment.